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[Objective] The present paper aimed to comprehensively and systematically study organic matter in arable soil as well as pH spatial distribution in the entire region of Guizhou, rationally plan and exploit cultivated land, and provide support for food security. [Method] Statistical analysis and ArcGIS space interpolation method were combined to analyze the spatial distribution of organic matter and pH in cultivated soil under the traditional cultivation pattern in Guizhou, and to study the influencing factors. [Result] The spatial distribution of soil organic matter content in cultivated land was uneven, with average content of 31. 13 g/kg, but the organic matter in cultivated land of Guizhou stayed abundant in general, and the content in each region showed as Liupanshui ( 52. 39 g/kg) > Guiyang ( 36. 01 g/kg) > Qianxinan (34. 02 g/kg) > Bijie(33. 89 g/kg) > Qiannan(32. 97 g/kg) > Anshun(31. 28 g/kg) > Qiandongnan(29. 92 g/kg) > Zunyi(25. 59 g/ kg) > Tongren(23. 01 g/kg). The pH of arable soil in Guizhou were 3. 99 - 8. 66, with the average value of 6. 06, and 90. 55% of the arable soils were dominantly acidic, weak acidic and neutral, accounting for 29. 48%, 38. 11 % and 22. 96% respectively. In the study area, the soil types display yellow-brown soil had the highest organic matter content and red soil had the lowest organic matter content The organic matter content with different soil utilization types was paddy field > irrigated land > dry land, while the pH showed as irrigated land > paddy field > dry land. [ Conclusion] The spatial distribution of organic matter content in arable soil of Guizhou province is uneven because of terrain, elevation and other influence factors, but the overall content stayed abundant. The spatial distribution of organic matter demonstrated as high in the west and south, low in the east and north. The pH of the provincial arable soil is mainly acidic or weak acidic, and its spatial distribution appeared uneven, showing a macro pattern of high in the west and north, low in the east and south. Soil type has a significant influence on pH of the soil, while it has insignificant impact on soil organic matter. Land utilizing type has extremely significant effect on both soil organic matter and pH. [ABSTRACT FROM AUTHOR]

[Objective] This paper aims to provide theoretical and technical support for the efficient pesticide application of spring potato in high altitude areas of Guizhou. [Method] A field experiment was conducted on Weiyu 5, to explore the effects of different pesticide application dosage on disease index and biological effect of spring potato in Guizhou. [Result] After spraying the potato seedling rate were 89. 63% — 93. 37%, the disease index were 2.71% — 6. 17%. Compared with CK, the yield, number of single tuber and the yield of single plant increased by 1.55% —22.97%,2. 50% —30.00%,and 12.29% —42.68%,respectively. The best performance was obtained with 80% of the customary spraying dose. Pesticide spraying can significantly improve reducing sugar and starch content of potato, increase the reducing sugar content by 0. 01 —0. 14 percentage and starch content by 0.76 —7.43 percentage compared with CK. But the nitrogen, phosphorus, potassium and moisture content were not obviously affected. In terms of soil nutrient changes, the contents of soil organic matter, available potassium, available phosphorus, and alkalize nitrogen were increased by 6. 96% — 15. 47%, 1 . 75 — 36. 84%, 3. 57% —56. 09% and 10. 00% —14.99% respectively compared with CK. [Conclusion] In summary, 80% of customary spraying dose is recommended for high-yielding dryland spring potato cultivation in Guizhou. [ABSTRACT FROM AUTHOR]

[Objective] The present paper aimed to understand chemical properties and available microelement characteristics of soil for growth of wild Bletilla striaes, explicit suitable soil environment of Bletilla.striaes cultivation and provide a reference for soil environment selection of Bletilla.striaes artificial cultivation. [Method] The microelement effective state and chemical properties of soil for growth of wild Bletilla.striata were investigated by field survey and the sufficient and lack level was analyzed by indoor analysis to discuss restriction factors affecting soil available microelement content. [Result] The pH and content of organic matter, total nitrogen, total phosphorus, total potassium, available nitrogen, available phosphorus, rapid available potassium, available Cu, available Zn, available Fe and available Mn in soil of Bletilla.striata cultivation are 7.65-7.99, 26.86-280.58 g/kg, 1.55-14.44 g/kg, 0.47-0.99 g/kg, 1.89-19.52 g/kg, 99-641 mg/kg, 2.40-18.75 mg/kg, 70-122 mg/kg, 0.45-1.70 mg/kg, 0.83-14.66 mg/kg, 11.80-119.85 mg/kg and 24.88-52.55 mg/kg respectively. [Conclusion] The suitable soil environment for Bletilla.striats growth is alkalescence and needs higher content of organic matter, total nitrogen, total phosphorus, available nitrogen, available phosphorus and rapid available potassium. The soil organic matter, N, P and K content has no obvious effect on Cu and Mn content in soil. The content of organic matter, total nitrogen, available nitrogen and available phosphorus in soil is positively related to Zn and Fe content very significantly.Selecting the soil with higher content of organic matter, total nitrogen, available nitrogen and available phosphorus can improve available Zn and Fe content in soil during Bletilla.striata artificial cultivation process, which is beneficial to growth and quality of Bletilla striata. [ABSTRACT FROM AUTHOR]